German Patent Specification No. 10353737 discloses a chain saw comprising a linear motion mechanism. In a chain saw of this type, the linear motion mechanism is used to adjust tension of a saw chain. The linear motion mechanism comprises a rotating shaft and a linear motion member that engages with a screw portion of the rotating shaft. The linear motion member engages with a guide bar. The saw chain is provided with tension between the guide bar and a body.
When adjusting the tension of the saw chain, an operator operates a wheel fixed to the rotating shaft. When the operator operates the wheel, the rotating shaft rotates and the linear motion member moves along the rotating shaft. As a result, the guide bar moves reciprocally relative to the body and the tension of the saw chain is adjusted.